Object Color Research Articles

Quaternion fast and accurate polar harmonic Fourier moments for color image analysis and object recognition

Image moments, as a kind of global feature descriptor of images, have become a valuable tool for pattern recognition and image analysis. However, traditional methods are mainly used to deal with grayscale images. In this paper, we apply quaternions to fast and accurate polar harmonic Fourier moments, proposing a kind of quaternion fast and accurate polar harmonic Fourier moment (QFAPHFM) capable of handling color images. Furthermore, this paper provides a detailed analysis of the invariance of QFAPHFMs under rotation, scaling, and translation transformations. The experimental results show that QFAPHFMs exhibit excellent performance in both image reconstruction and object recognition tasks. QFAPHFMs achieve accurate image reconstruction under noiseless and noisy conditions, and demonstrate excellent recognition performance in the color-based object recognition tasks.

Применение свёрточных нейронных сетей в задаче устранения теней с фотографий

<p>The article proposes a method for removing shadows from photographs using deep learning methods. The proposed method consists of several stages: dividing the image into rectangular fragments of 32x32 pixels, localizing shadows on each fragment, restoring the color of shadowed objects, and combining the fragments back into a whole image. Shadow localization is considered as a semantic segmentation problem; to solve it, a neural network of encoder-decoder architecture has been developed and trained. To restore the color of objects in identified shaded areas, another neural network based on the CDNet architecture is used. Examples of image processing using the developed method are given, including images from a drone, and the high quality of restoration of shaded areas is demonstrated.</p>

Machine vision-based online detection method for color characteristics of cobalt extraction solution

Cobalt, as a rare metal, plays an important role in strategic resources due to its physical, chemical, and mechanical properties in applications. In order to achieve automatic control of the cobalt extraction process, it is necessary to conduct online detection of the color characteristics of the cobalt extraction solution. Unfortunately, due to the lack of online automatic detection methods for the color of cobalt extraction solution, the automatic control of the extraction process has not yet been achieved. Currently, the color of cobalt extraction solution needs to be observed and judged by operators based on experience. This will result in significant detection errors and time lag. To change this situation, an online detection method for color features of cobalt extraction solution based on machine vision is proposed in this article. Firstly, we establish a real-time image acquisition environment for detecting object colors, and then use the Gaussian filters and K-means algorithm to denoise and segment the image. In order to correct color distortion in images caused by ambient light, we measure the color feature values of a set of standard color cards using the machine vision system and a standard spectrophotometer. Based on this test data, we establish chromaticity correction models for the extraction solution using back propagation (BP) network and radial basis function (RBF) network, respectively. The models can correct the color characteristic values of the extraction solution, overcome environmental interference, and thus obtain more accurate color characteristic values of the extraction solution. The established model can be used for online automatic color detection of cobalt extraction solution. The modeling results indicate that in the established color measurement environment, the RBF network model outperforms the BP network model in color feature detection accuracy.

ALAT PERAGA ELEKTRONIK BERBASIS ARDUINO DENGAN KELUARAN CAHAYA DAN SUARA UNTUK PENGENALAN WARNA BAGI BALITA

Recognizing the color of an object is a basic thing that must be taught to toddlers. This research aims to design and realize a color recognition teaching aids for toddlers, designed using an electronic device based on an Arduino Uno microcontroller with output in the form of audio sound and light. This tool consists of: an object in the form of a colorful plastic ball, an input device in the form of a TCS230 color sensor, a processing and controlling device in the form of an Arduino Uno microcontroller, and output devices in the form of a DC servo motor, RGB LED strip, and loudspeaker. Based on the results of measurements and tests that have been carried out, the Arduino Uno microcontroller can function to control all input and output devices. The TCS230 color sensor successfully detected the color pixel value (RGB) of the object, and issued wavelength information in the form of frequency quantities. The DC servo motor can move to direct the object to the mouth of the slide pipe. The loudspeaker can produce audio sounds according to the name of the object's color. RGB LED strips can emit light according to the color of the object. Overall, the results of the design and realization, measurement and testing of color recognition teaching aids for toddlers are in accordance with what was planned.

Self‐Powered Multimodal Sensing Using Energy‐Generating Solar Skin for Robotics and Smart Wearables

Wearable electronic devices‐laden systems such as electronic‐skin (e‐Skin) have been explored in recent years to enable advances in applications such as Internet of Things, healthcare, and robotics. The power requirement of multitudes of devices in the e‐Skin is a major hurdle for its wider uptake. Herein, a solar cells‐based energy generating e‐Skin is presented and how the energy outputs of solar cells can be innovatively processed for multimodal sensing is demonstrated. By reading the variations and energy output patterns of the e‐Skin, present on a robotic arm, multiple parameters can be sensed including object motion, color detection, and ambient temperature. With the accurate tracking of shadow sensing, for an object moving in horizontal and vertical directions with respect to the solar skin, information can be obtained such as the velocity and acceleration of moving object. In this regard, the presented e‐Skin can also be seen to have vision capability. The presented multifunctional energy‐generating e‐Skin shows an energy surplus of >1 mW (effective module area of 20 cm2) under white light illumination of 4,450 lux, which is sufficient for continuous powering of portable low‐powered devices. Finally, we demonstrate the e‐Skin application for energy‐autonomous hand gestures recognition in robotics.

Comparative Analysis of RGB and CIELAB Colour Spaces in Quality Assessment of Brick Products

Methods for assessing the colour (quality) of manufactured products, as a rule, are aimed at analysing the data obtained by colorimeters or spectrometers for the objects under study. The problematic side of such measurements is the small area of the object affected by the measurements. The introduction to the practice of evaluating the colour of the produced image products makes it possible to evaluate the colour of the entire object, while leaving the traditional measurement methods for verifying the obtained colour characteristics from the image. The typical colour space for images is RGB, and for colorimeters LAB. Naturally, when applying the image method, it becomes necessary to convert from the RGB to LAB colour space in order to obtain colour indicators that can be compared with colorimeters. The article provides a description of the obtained colour characteristics when assessing the quality of brick products.

Artificial Intelligence in Graphic Design: the Case of Generative Neural Networks

The purpose of the article is in finding out the level of influence of Artificial Intelligence on the graphic design on the example of operationalization of neural networks, which made generative graphics possible, allowed for a high variability of parameters, as well as adjusting the color scheme, contrast, and geometric proportions of the objects being created. Research methods. The empirical method, the method of analysis and synthesis, as well as qualitative research methods were used, which, in particular, include the study of scientific, popular and web sources on the use of generative networks and AI in graphic design; the features and functional parameters of individual neural networks in the context of the topic of the article were analyzed. In addition, along with a review of the latest research on the topic, the relationship between experimental and scientific research in graphic design today and the development of generative design as a promising technology with a wide range of applications and a method for designing functional structures of graphic design, UI/UX design, animation, etc. is clarified. Scientific novelty. The article presents for the first time a comprehensive approach to the problem of applying AI and generative neural networks in graphic design, and considers, in particular, the potential, advantages, and disadvantages of specific neural networks, such as DALL-E, DALL-E 2, Stable Diffusion, MidJourney, and Craiyon, when generating compositional and graphic solutions. Conclusions. It was found out that generative neural networks are one of the most popular types of AI in the design industry in the first quarter of the twenty-first century. Neural networks such as DALL-E, DALL-E 2, Stable Diffusion, MidJourney, and Craiyon, or professional programs such as InDesign or Illustrator, have definitely become indispensable for many graphic designers today, who use them to reproduce, transform, and synthesize images, manipulate elements according to the needs of users, improve and edit variations of generated images, as well as adjust geometric proportions, color and contrast of objects, and use a high variability of parameters.

Objective sputum colour assessment and clinical outcomes in bronchiectasis: data from the European Bronchiectasis Registry (EMBARC).

A validated 4-point sputum colour chart can be used to objectively evaluate the levels of airway inflammation in bronchiectasis patients. In the European Bronchiectasis Registry (EMBARC), we tested whether sputum colour would be associated with disease severity and clinical outcomes. We used a prospective, observational registry of adults with bronchiectasis conducted in 31 countries. Patients who did not produce spontaneous sputum were excluded from the analysis. The Murray sputum colour chart was used at baseline and at follow-up visits. Key outcomes were frequency of exacerbations, hospitalisations for severe exacerbations and mortality during up to 5-year follow-up. 13 484 patients were included in the analysis. More purulent sputum was associated with lower forced expiratory volume in 1 s (FEV1), worse quality of life, greater bacterial infection and a higher bronchiectasis severity index. Sputum colour was strongly associated with the risk of future exacerbations during follow-up. Compared to patients with mucoid sputum (reference group), patients with mucopurulent sputum experienced significantly more exacerbations (incident rate ratio (IRR) 1.29, 95% CI 1.22-1.38; p<0.0001), while the rates were even higher for patients with purulent (IRR 1.55, 95% CI 1.44-1.67; p<0.0001) and severely purulent sputum (IRR 1.91, 95% CI 1.52-2.39; p<0.0001). Hospitalisations for severe exacerbations were also associated with increasing sputum colour with rate ratios, compared to patients with mucoid sputum, of 1.41 (95% CI 1.29-1.56; p<0.0001), 1.98 (95% CI 1.77-2.21; p<0.0001) and 3.05 (95% CI 2.25-4.14; p<0.0001) for mucopurulent, purulent and severely purulent sputum, respectively. Mortality was significantly increased with increasing sputum purulence, hazard ratio 1.12 (95% CI 1.01-1.24; p=0.027), for each increment in sputum purulence. Sputum colour is a simple marker of disease severity and future risk of exacerbations, severe exacerbations and mortality in patients with bronchiectasis.

Antimicrobial efficacy of a citric acid/hydrochloric acid blend, peroxyacetic acid, and sulfuric acid against Salmonella and background microbiota on chicken hearts and livers.

This study aimed at evaluating the efficacy of a blend of citric acid and hydrochloric acid (CP), peroxyacetic acid (PAA), and sulfuric acid (SA) against Salmonella and mesophilic aerobic plate counts (APC) on chicken hearts and livers. Samples were inoculated with a five-serovar cocktail of Salmonella at ca. 4.8logCFU/g and treated by immersion with a water control (90s), CP (5% v/v, 30s), PAA (0.05% v/v or 500ppm, 90s), or SA (2% v/v, 30s), all at 4°C and with mechanical agitation. Samples were vacuum packed and stored for up to 3 days at 4°C. Three independent replications were performed for each product, treatment, and time combination. The average Salmonella reductions in chicken hearts after 3 days were 1.33±0.25, 1.40±0.04, and 1.32±0.12logCFU/g for PAA, SA, and CP, respectively. For chicken livers, the values were 1.10±0.12, 1.09±0.19, and 0.96±0.27 for PAA, SA, and CP, respectively. All antimicrobials reduced Salmonella counts in both chicken hearts and livers by more than one log, in contrast to the water control. All treatments effectively minimized the growth of APC for up to 3 days of refrigerated storage, and no differences in objective color values (L, a, or b) were observed. The poultry industry may use these antimicrobials as components of a multifaceted approach to mitigate Salmonella in nonconventional chicken parts.

Spectrum mapping technology based creation of a color-contrast reading environment to reach comfort and clarity

Reading with a bit of yellowish or greenish paper, as compared to white paper, is thought to be more comfortable and friendly, and can help decrease eye fatigue to some degree. In this work, we try to map the light of different colors on a given paper within a region of interest to alter the colors presented by the paper and consequently influence the reading experience. We conducted an ergonomic experiment to study the comfort and clarity under consistent illuminance levels. We adopted 6 color series(red, yellow, green, cyan, blue, and magenta), 5 chroma levels(0, 10, 20, 30, 40), and 4 types of paper with the same hue(yellow) but different lightness(the white, light yellow, yellow, and dark yellow), and conducted pairwise selection experiments within each light color series. Results show that white and low chroma (≈10) color characteristics contribute to comfort, while higher chroma blue(30∼40) color benefits clarity. Referring to white, low chroma greenish and yellowish color characteristics are preferred in terms of comfort and clarity. This work proposes the spectrum mapping technology to endow the paper with new color effects and verifies that although spectrum compositions might differ, people’s preferences and comfort perception are consistent with the same object color.

Functional opsin patterning for Drosophila color vision is established through signaling pathways in adjacent object-detection neurons.

Vision is mainly based on two different tasks, object detection and color discrimination, carried out by photoreceptor (PR) cells. The Drosophila compound eye consists of ∼800 ommatidia. Every ommatidium contains eight PR cells, six outer cells (R1-R6) and two inner cells (R7 and R8), by which object detection and color vision are achieved, respectively. Expression of opsin genes in R7 and R8 is highly coordinated through the instructive signal from R7 to R8, and two major ommatidial subtypes are distributed stochastically; pale type expresses Rh3/Rh5 and yellow type expresses Rh4/Rh6 in R7/R8. The homeodomain protein Defective proventriculus (Dve) is expressed in yellow-type R7 and in six outer PRs, and it is involved in Rh3 repression to specify the yellow-type R7. dve mutant eyes exhibited atypical coupling, Rh3/Rh6 and Rh4/Rh5, indicating that Dve activity is required for proper opsin coupling. Surprisingly, Dve activity in R1 is required for the instructive signal, whereas activity in R6 and R7 blocks the signal. Our results indicate that functional coupling of two different neurons is established through signaling pathways from adjacent neurons that are functionally different.

Color Authenticity for the Sustainable Development of Historical Areas: A Case Study of Shiquan

Currently, historical areas in China are facing issues of color authenticity and excessive commercialization. Colors, as an important element of historical areas, reflect their history and culture. However, there are some flaws in the existing research methods, so a more scientific and systematic method is needed to obtain accurate and objective color visualization results to promote the sustainable development of historical areas. In order to explore the methods and applications of visualizing the environmental color patterns of historical areas, Shiquan Street in Suzhou, China, was taken as the research object; ArcGIS 10.5 was used to obtain the street-view photo samples; Matlab was used to summarize the architectural colors of the historical areas; and K-means clustering was used to generate the central color card of the historical areas, thus completing the color visualization of the historical areas, followed by further searching for the color patterns and central colors, so as to explore the strategies for sustainable development of historical areas. The various quantified color models of historical areas can explore the regional uniqueness and color locality of historical areas, which avoids problems such as homogenization of block colors, unclear styles and features, and an excessive proportion of commercial colors caused by poor color guidance and control in the design related to historical areas, providing approaches to the research on the harmonious unity of environmental colors and features related to historical areas. A color-based research method has been proposed to protect and maintain the original appearance of historical areas. The application of this method provides a new perspective and possibility for the protection of historical areas, allowing these areas to achieve historical sustainability while maintaining their historical characteristics and values.

Effect of Electrostatic Field Assisted Thawing on the Quality of Previously Frozen Beef Striploins

The objective of this study was to evaluate the impact of applying electrostatic field (EF)–assisted thawing on the quality attributes of previously frozen beef striploin. Beef striploins from both sides of 12 USDA Choice carcasses were halved, frozen at −40°C, and thawed under 4 EF voltage treatments: 0 kV (control), 2.5 kV, 5 kV, and 10 kV. After reaching the internal temperature of −1°C, striploins were weighed for yield calculation, swabbed for microbial analysis, fabricated into steaks, and assigned to either 0- or 14-d aging period and retail displayed for 0 or 7 d. Subjective and objective color measurements were taken during the retail display. Upon completion of retail display, Warner-Bratzler shear force (WBSF), cook loss, sarcomere length, troponin-T degradation, muscle fiber spacing, lipid oxidation, antioxidant capacity, pH, and proximate analysis were performed. All EF treatments increased purge loss compared to the control (P&amp;lt;0.05) and did not improve thawing speed, with samples from 10 kV actually taking the longest to thaw (P&amp;lt;0.05). The 2.5 kV and 5 kV samples aged 14 d showed less discoloration than those from 0 kV and 10 kV, and 5 kV samples aged 14 d had higher a* than those from the other treatments (P&amp;lt;0.05). Samples thawed under 10 kV showed a reduction in WBSF compared to the control (P&amp;lt;0.05), but there was no impact of EF on aerobic plate count, sarcomere length, troponin-T degradation,relative fat %, crude protein %, moisture %, purge protein concentration, pH, lipid oxidation, or antioxidant capacity for either the hydrophilic (water soluble) and lipophilic (lipid soluble) portion of the samples (P&amp;gt;0.05). Overall, our study determined that there was no economic benefit to apply EF during thawing regarding yield and purge loss. However, the application of EF may improve tenderness and extend shelf life of beef during retail display.

SENSORY INTEGRATION AND ITS SIGNIFICANCE FOR CHILD DEVELOPMENT

The article is devoted to highlighting the features of sensory integration manifestation in childhood and its significance for the holistic development of the child. This includes uncovering the characteristics and patterns of mental development during childhood, describing the main stages of sensory integration development in ontogenesis, and examining sensory integration disorders and the application of sensory integrative therapy with children. A review of foreign and domestic literature on the research problem has shown that there is a growing interest in sensory integration in modern psychology as the foundation for a child's holistic development. Sensory integration is a process occurring in the brain that organizes information received through the senses (vision, hearing, touch, smell, taste), gives meaning to these sensations by filtering information, selecting what to focus on, and enabling us to act and react thoughtfully to the situation we are in. It also forms the basis for theoretical learning and social behavior. The harmonious development of a child depends on the coordinated functioning of all sensory systems. The article explores the features and patterns of mental development in childhood, such as heterochrony, asynchrony, staging, differentiation, and integration of mental processes and properties, as well as changes in the determinants of mental development and plasticity. The main stages of sensory integration development in ontogenesis are also examined. The importance of the sensory-perceptual sphere in a child’s development is underscored, as sensory development is the foundation of a child’s intellectual growth. Sensory development involves the development of sensations and perceptions, as well as the understanding of objects' forms, colors, sizes, and spatial locations, as well as the objects and phenomena of the surrounding world. Perception is formed based on the synthesis of various sensations: visual, auditory, tactile, kinesthetic, olfactory, and others. Perception reflects the objectivity, integrity, structure, constancy of objects, and others. Early childhood is the most favorable period for the improvement of sensory organ functions and the accumulation of representations about the surrounding world. Knowledge of the surrounding reality in children begins with the analysis of information received through touch, visual observation, sounds, smells, various tastes, and so on. It has been established that childhood plays a crucial role in sensory integration, as a child organizes not only visual and auditory sensations but also the sensations of their own body and the force of gravity, which contributes to the child’s holistic development. A significant portion of a child’s learning ability lies in their ability to integrate sensory information, as learning depends on the ability to perceive and process sensations from their movements and external influences and to use this information for planning and organizing behavior. It has been found that sensory integration facilitates the development of motor skills, movement coordination, spatial orientation, and visual and auditory perception, particularly by filtering and organizing information to help the child focus on solving specific tasks. Moreover, sensory integration contributes to the development of cognitive mental processes: attention, memory, thinking, and speech. Sensory integration also enhances a child's adaptation to the environment, social interaction, communication, and the formation of independence and curiosity in the child. Sensory integration disorders (hyposensitivity and hypersensitivity of sensory systems) have been analyzed, and the main principles of sensory-integrative therapy with children have been outlined. Children with reduced sensory processing abilities often experience difficulties in carrying out voluntary actions, which in turn can affect learning and behavior. Therefore, sensory-integrated therapy aimed at developing and integrating sensations contributes to improving the child’s learning and behavior. In conclusion, sensory integration is of great importance for child development.

Color constancy in real-world settings.

Color constancy denotes the ability to assign a particular and stable color percept to an object, irrespective of its surroundings and illumination. The light reaching the eye confounds illumination and spectral reflectance of the object, making the recovery of constant object color an ill-posed problem. How good the visual system is at accomplishing this task is still a matter of heated debate, despite more than a 100 years of research. Depending on the laboratory task and the specific cues available to observers, color constancy was found to be at levels ranging between 15% and 80%, which seems incompatible with the relatively stable color appearance of objects around us and the consistent usage of color names in real life. Here, we show close-to-perfect color constancy using real objects in a natural task and natural environmental conditions, chosen to mimic the role of color constancy in everyday life. Participants had to identify the color of a (non-present) item familiar to them in an office room under five different experimental illuminations. They mostly selected the same colored Munsell chip as their match to the absent object, even though the light reaching the eye in each case differed substantially. Our results demonstrate that color constancy under ideal conditions in the real world can indeed be exceptionally good. We found it to be as good as visual memory permits and not generally compromised by sensory uncertainty.

White matter network underlying semantic processing: evidence from stroke patients.

The hub-and-spoke theory of semantic representation fractionates the neural underpinning of semantic knowledge into two essential components: the sensorimotor modality-specific regions and a crucially important semantic hub region. Our previous study in patients with semantic dementia has found that the hub region is located in the left fusiform gyrus. However, because this region is located within the brain damage in patients with semantic dementia, it is not clear whether the semantic deficit is caused by structural damage to the hub region itself or by its disconnection from other brain regions. Stroke patients do not have any damage to the left fusiform gyrus, but exhibit amodal and modality-specific deficits in semantic processing. Therefore, in this study, we validated the semantic hub region from a brain network perspective in 79 stroke patients and explored the white matter connections associated with it. First, we collected data of diffusion-weighted imaging and behavioural performance on general semantic tasks and modality-specific semantic tasks (assessing object knowledge on form, colour, motion, sound, manipulation and function). We then used correlation and regression analyses to examine the association between the nodal degree values of brain regions in the whole-brain structural network and general semantic performance in the stroke patients. The results revealed that the connectivity of the left fusiform gyrus significantly predicted general semantic performance, indicating that this region is the semantic hub. To identify the semantic-relevant connections of the semantic hub, we then correlated the white matter integrity values of each tract connected to the left fusiform gyrus separately with performance on general and modality-specific semantic processing. We found that the hub region accomplished general semantic processing through white matter connections with the left superior temporal pole, middle temporal gyrus, inferior temporal gyrus and hippocampus. The connectivity between the hub region and the left hippocampus, superior temporal pole, middle temporal gyrus, inferior temporal gyrus and parahippocampal gyrus was differentially involved in object form, colour, motion, sound, manipulation and function processing. After statistically removing the effects of potential confounding variables (i.e. whole-brain lesion volume, lesion volume of regions of interest and performance on non-semantic control tasks), the observed effects remained significant. Together, our findings support the role of the left fusiform gyrus as a semantic hub region in stroke patients and reveal its crucial connectivity in the network. This study provides new insights and evidence for the neuroanatomical organization of semantic memory in the human brain.

CATARACT SYMPTOMS SCALE AS A SCREENING TOOL FOR VISION DISORDERS DUE TO CATARACT BY NON-MEDICAL CADRES

Introduction: Cataract is an eye disease with clouding of the lens causing visual interference. Blindness due to cataracts is still the leading cause of blindness in the world. Cataract screening using the questionnaire integrated interview method can be an easy instrument for non-medical cadres to use. Cataract Symptoms Scale (CSS) is a complaint-based questionnaire in cataract patients which is used to screen for visual disturbances due to cataracts.&#x0D; Objective: To find out whether CSS has good validity as a screening tool for visual impairment due to cataracts by non-medical cadres.&#x0D; Methods: This study used a diagnostic test to assess the accuracy of CSS. All respondents who met the inclusion and exclusion criteria were included as research subjects.&#x0D; Results: 151 respondents included in the vision screening activity of the Community Ophthalmology Unit of Cicendo Eye Hospital. Respondents with cataracts in this study amounted to 59 (39.07%) and non-cataracts amounted to 92 (40.93%). The most complaints of respondents were blurry with 145 complaints and the least complaints were changes in the color of objects, namely 36 complaints. The CSS questionnaire sensitivity value of 61.01% indicates a weak value statistically. The specificity value of 78.26% indicates a moderate specificity value statistically. The positive predictive value of 64.28% indicates a statistically weak NDP value. The negative predictive value of 75.78% indicates a statistically moderate value. The value of accuracy is 71.52% statistically moderate.&#x0D; Conclusions: The Cataract Symptoms Scale has poor validity to be used by non-medical cadres as a screening tool for patients with visual impairment due to cataracts. Further research is needed by adjusting the components of the questionnaire and adding variables such as visual acuity and cataract laterality.

Whitening efficacy of activated charcoal-based products: A single-blind randomized controlled clinical trial

ObjectiveThis randomized controlled clinical trial evaluated the whitening efficacy, tooth sensitivity (TS), and volunteers’ satisfaction following the use of activated charcoal powder and toothpaste. MethodsFifty-six volunteers were randomly allocated into 4 groups (n = 14) according to a 14-day toothbrushing or whitening treatment with activated charcoal powder (ACPW), activated charcoal toothpaste (ACT), regular fluoridated toothpaste (RT), and 10 % carbamide peroxide (CP). Objective (ΔE00) and subjective (ΔSGU) color and whiteness index (ΔWID) changes were calculated. Patients self-reported the risk and intensity of TS using a visual analogue scale and the volunteer's satisfaction was determined by a questionnaire. Color assessments were analyzed by Kruskal-Wallis followed by Dwas-Steel-Crithlow-Fligner, and absolute TS risk and volunteer's satisfaction by Fisher exact test (p < 0.05). ResultsACPW and ACT promoted similar effects in ΔE00, ΔSGU, and ΔWID to that observed for RT. No significant difference was found in terms of TS risk intensity. TS risk became high after 7 and 14 days, with higher TS prevalence in CP. Volunteers reported that ACPW exhibited the lowest ease-of-use, comfort, and whitening satisfaction among groups (p < 0.05). ConclusionActivated charcoal-based products presented a minor and unsatisfactory whitening effect while CP resulted in optimal tooth whitening and the highest level of satisfaction among volunteers. Risk was higher from 7 days onwards and was more pronounced in the CP. Clinical relevanceBased on the whitening effect and patient satisfaction, this controlled-randomized clinical evidence supports that the use of activated charcoal-based products should be discouraged.

Identification of optimal flap types for color matching in free flap-based facial reconstruction in Asian population

Large soft tissue defects of the face often require free flap-based reconstruction. To avoid a conspicuous patch-like appearance, choosing flaps with a color similar to that of the adjacent facial skin is crucial. This study aimed to identify the flap types that show the best color match via objective color evaluation.Patients who underwent free flap-based facial reconstruction between 2013 and 2023 were retrospectively reviewed. Based on standardized photographs, average color samples of the flap skin paddle and adjacent skin were obtained. The color differences were compared by flap type at two different time points, early (within 1–3 months, post-operative) and late (after 1 year, post-operative), using the delta E value.Fifty-eight free flaps were analyzed, including 22 thoracodorsal artery perforator (TDAP) flaps, 17 anterolateral thigh (ALT) flaps, nine superficial circumflex iliac artery perforator (SCIP) flaps, and eight radial forearm (RF) flaps. In the analysis of early outcomes, the RF flaps showed the least color difference, followed by the SCIP and TDAP flaps, and the ALT flaps showed the greatest difference, with the differences being significant. Most cases showed generally improved color matching over time. Time-dependent changes were significant in the ALT and TDAP flap groups. In the analysis of late outcomes, all flap types showed delta E values less than 10, with the RF flaps showing the least color difference, followed by the SCIP flap. The four workhorse flaps provided acceptable outcomes with long-term improvements. The RF flaps provided the best color matching in the long run.

Contralateral delay activity and alpha lateralization reflect retinotopic and screen-centered reference frames in visual memory

The visual system represents objects in a lateralized manner, with contralateral cortical hemispheres responsible for left and right visual hemifields. This organization extends to visual short-term memory (VSTM), as evidenced by electrophysiological indices of VSTM maintenance: contralateral delay activity (CDA) and alpha-band lateralization. However, it remains unclear if VSTM represents object locations in gaze-centered (retinotopic) or screen-centered (spatiotopic) coordinates, especially after eye movements. In two experiments, participants encoded the colors of target objects and made a lateral saccade during the maintenance interval, thereby shifting the object’s location on the retina. A non-lateralized probe stimulus was then presented at the new fixation for a change detection task. The CDA maintained lateralization towards the target’s original retinotopic location, unaffected by subsequent saccades, and did not invert polarity even when a saccade brought that location into the opposite hemifield. We also found conventional alpha lateralization towards the target’s location before a saccade. After a saccade, however, alpha was lateralized towards the screen center regardless of the target’s original location, even in a control condition without any memory requirements. This suggests that post-saccadic alpha-band lateralization reflects attentional processes unrelated to memory, while pre- and post-saccade CDA reflect VSTM maintenance in a retinotopic reference frame.